what do the 4x4 lites do on the dash?
if its esof(electronic shift on the fly, its more than likely the shift motor or the actuator and fork to engage the frt end, you will have to retrieve codes from the 4x4 module to know which one, if its msof( manual shift on the fly) its probably the actuator in the frt.

Put into 4L went a little ways then put back into 2H. went about 100ft and then
it was like the car was in neutral. Now It wont go in reverse or any other gear.
The shifter moves but it never feels ...